Physical and Chemical Changes
Which example would most likely suggest a new substance was formed?
A a substance changing shape when bent
B a substance changing color after dye was added
C a substance giving off bubbles without being heated
D a substance going from solid to liquid when heat was added
C a substance giving off bubbles without being heated
A student adds water and sugar to a jar and seals the jar so that nothing can get in or out. The student then weighs the jar containing the water and sugar. After some sugar dissolves, the student weighs the jar and its contents again. What will happen to the weight of the jar containing the water and sugar after some of the sugar dissolves?
a. The weight will stay the same.
b. The weight will increase.
c. The weight will decrease.
d. The weight will depend on how much sugar dissolves.
a. The weight will stay the same.
Why are liquids sometimes used in a thermometer?
a. because most liquids condense when heated and evaporate when cooled
b. because most liquids melt when heated and freeze when cooled
c. because most liquids contract when heated and expand when cooled
d. because most liquids expand when heated and contract when cooled
d. because most liquids expand when heated and contract when cooled
A pan with a metal handle is left on a hot stove. The handle becomes very hot. What would help keep the handle cool to touch?
A. Wrapping the handle in foil
B. Using a thicker metal for the handle
C. Covering the handle with rubber or wood
D. Making the handle longer
C. Covering the handle with rubber or wood
David left a metal shovel outside in the yard. Over time, he noticed that the shiny metal surface had turned reddish-brown, and rough patches appeared. Which of David’s observations is evidence that a new substance has formed?
a. The shovel was left outside.
b. The metal changed color and developed rough patches.
c. The shovel was used to dig in the soil.
d. The metal became cold in the winter.
b. The metal changed color and developed rough patches.
Anthony is performing an experiment. He adds 0.25 grams of baking soda to 5 grams of water and stirs. Anthony watches as the baking soda dissolves in the water. If Anthony weighs the water and baking soda solution, what will its mass be?
a. 4.75 grams
b. 5.0 grams
c. 5.25 grams
d. 7.5 grams
c. 5.25 grams
Which of the following is an example of thermal expansion?
a. A metal spoon getting shorter when placed in hot soup
b. A rubber band becoming tighter when exposed to cold temperatures
c. A glass jar cracking when filled with hot liquid
d. A balloon shrinking when placed in a freezer
c. A glass jar cracking when filled with hot liquid
You touch the metal part of a spoon that’s been sitting in hot soup, and it feels very warm. What does this tell you about metal?
A. Metal is a good conductor of heat.
B. Metal holds in heat and doesn’t release it.
C. Metal reflects heat away.
D. Metal is a thermal insulator.
A. Metal is a good conductor of heat.
Jordan collects some gold, white, and red rocks into a bucket. Then, he shakes the bucket so that the rocks are mixed. Jordan claims the rock mixture is a new substance. Why is Jordan’s claim incorrect?
a because some of the rocks might have changed shape
b. because the rocks made noise as he shook the bucket
c. because he could separate individual rocks from the mixture
d. because the mixture is only made of solids
c. because he could separate individual rocks from the mixture
A ball of play-doh is torn into pieces. Which statement can be used to compare the mass of the play-doh before and after it is torn?
a. The total mass cannot be determined after the play-doh has been torn to pieces.
b. The total mass of the pieces of play-doh is less than the mass of the ball of play-doh.
c. The total mass of the pieces of play-doh is equal to the mass of the ball of play-doh.
d. The total mass of the play-doh is greater than the mass of the ball of play-doh.
c. The total mass of the pieces of play-doh is equal to the mass of the ball of play-doh.
Adrien fills a glass container completely with water and screws the lid on tightly. He places the container in a freezer. Which will most likely result?
a. The container will prevent the water from freezing.
b. The water will freeze and take up less space in the container.
c. The water in the container will expand when it freezes and cause the container to crack.
d. The container will absorb heat from the water, causing it to crack.
c. The water in the container will expand when it freezes and cause the container to crack.
To keep from burning a hand on a pot handle, of which material should the handle be made?
a. aluminum because it is a good conductor of heat
b. glass because it is a good conductor of heat
c. iron because it is a poor conductor of heat
d. rubber because it is a poor conductor of heat
d. rubber because it is a poor conductor of heat
Which investigation would provide evidence of a chemical change and why?
a. Melting a solid with fire would provide evidence of a chemical change because the solid would change shape.
b. Cutting cardboard into many smaller pieces would provide evidence of a chemical change because the pieces cannot be put back together.
c. Placing a solid into hot water and stirring while the solid dissolves would provide evidence of a chemical change because the dissolved material is lost.
d. Combining two liquids that give off heat and gas would provide evidence of a chemical change because the particles react to make a new material with different properties.
d. Combining two liquids that give off heat and gas would provide evidence of a chemical change because the particles react to make a new material with different properties.
Bonnie had a rubber ball that weighed 10 ounces. She placed it outside, then later noticed the ball was warm. Which choice describes the weight of the warm rubber ball?
a. The warm rubber ball should weigh 10 ounces.
b. The warm rubber ball should weigh more than 10 ounces.
c. The warm rubber ball should weigh less than 10 ounces.
d. The warm rubber ball’s weight cannot be determined.
a. The warm rubber ball should weigh 10 ounces.
Sarah left a fully inflated balloon in her car on a hot summer afternoon. When she returned to the car, she noticed the balloon had expanded and felt firm. Later that evening, when the temperature dropped, she saw that the balloon had shrunk and become softer. What can Sarah conclude based on this information?"
a. The balloon expanded because it lost heat.
b. The balloon shrank because it gained heat.
c. The balloon expanded, causing it to gain heat during the day.
d. The balloon expanded because it gained heat as the temperature increased.
d. The balloon expanded because it gained heat as the temperature increased.
Why are some materials considered to be good conductors of heat?
a. because they can quickly transfer heat
b. because they easily bend when heated
c. because they absorb heat without touching an object
d. because they require a great amount of heat to melt
a. because they can quickly transfer heat
Choose 3 examples of a change in which a new substance is formed.
a. Sugar dissolving into water
b. Baking a cake in the oven
c. Ice melting and becoming a liquid
d. Metal changing shape when heated
e. Rust forming on a bicycle
f. Wood burning and turning to ash
g. Water evaporating into the air
b. Baking a cake in the oven
e. Rust forming on a bicycle
f. Wood burning and turning to ash
A student fills a glass with 300 mL of water and leaves it outside on a warm, sunny day. The next day, the student checks the glass and sees that only 200 mL of water is left. What most likely happened to the missing water?"
a. 100 mL of water turned into water vapor and evaporated.
b. The glass absorbed the missing water.
c. The air turned the water into ice.
d. 100 mL of water was added overnight.
a. 100 mL of water turned into water vapor and evaporated.
A copper wire is heated over a flame. This table shows the measurements of the wire after it has been in the flame for 8 minutes. Which statement is supported by the data collected?
Minutes Length in cm
4 minutes 15 cm
8 minutes 21 cm
a. When the wire is heated, it becomes longer.
b. When the wire is heated, it becomes shorter.
c. Longer wires warm up more quickly than shorter wires.
d. Shorter wires warm up more quickly than longer wires.
a. When the wire is heated, it becomes longer.
Two materials are being tested to create oven mitts. The material is heated for 10 minutes and the temperature is recorded in the chart below. Based on the data collected, which material would be better for making oven mitts?
Time Material 1 Temp Material 2 Temp
0 minutes 25 F 25 F
5 minutes 27 F 45 F
10 minutes 28 F 65 F
a. Material 1, because it had a greater temperature change than Material 2.
b. Material 1, because it had a smaller temperature change than Material 2.
c. Material 2, because it had a greater temperature change than Material 1.
d. Material 2, because it had a smaller temperature change than Material 1.
b. Material 1, because it had a smaller temperature change than Material 2.